Artificial intelligence (AI), a concept once confined to the realms of science fiction, has in the last several years entered the mainstream – with the release of OpenAI’s inaugural ChatGPT model, and other competitor engines subsequently, transforming innumerable
industries.
Often uttered in conjunction with ‘AI’ is the term ‘deep learning’, though its nature and use cases may be less clear to the layman. While AI is a broad field encompassing a machine's capacity to perform tasks historically necessitating human intelligence,
deep learning is a subset of machine learning (ML) which leverages artificial neural networks with multiple layers to learn from complex datasets.
According to the third
survey on AI and ML in UK financial services by The Bank of England and the Financial Conduct Authority (FCA), published in November 2024, 75% of firms are already using AI, with a further 10% planning to use it over the next three years. Foundation models
form 17% of all AI use cases supporting anecdotal evidence for the rapid adoption of this complex type of machine learning.
But what’s the draw? How does deep learning work exactly? What is its relevance to financial services? This short read explores the phenomenon of deep learning; its structures, models, applications, and broad use cases.
The inner workings
Deep learning is a specific kind of ML, which leverages artificial neural networks – as opposed to algorithms – to glean patterns from complex or unstructured datasets.
Neural networks are inspired by the structure of the human brain; comprising a collection of nodes, each is its own processing unit. By passing data that is statistically significant from one layer of nodes to the next, neural networks can train themselves
to recognise patterns in information and make predictions, with little human intervention.
Neural networks are typically split into three layers:
- Input layer
The nodes in this layer receive and process input data – be it structured, unstructured, multi-media, plain text, or other.
- Hidden layer
This slice is sometimes composed of hundreds of subset layers. It receives data from the input layer and processes at different levels, analysing the problem from numerous perspectives and adapting its behavior as new learnings are gleaned.
- Output layer
The nature of the output layer depends on the system and its goal. A “yes” or “no” (binary) output model, for example, would only require two nodes. More complex systems, such as Generative AI (GenAI), would require a highly complex set of nodes, in order
to deliver nuanced outputs and unstructured information – videos, images, or analyses.
The unique architecture of deep learning technology makes it the delivery engine behind many everyday AI systems, such as chatbots and code generators, digital assistants, fraud detectors, and facial recognition.
The models
Deep learning systems can be arranged in many different models. The three most common are:
- Convolutional neural network (CNN)s
CNNs excel at identifying objects in images – even when they are obscured or distorted. As such, image recognition and processing are the domain of CNNs.
- Deep reinforcement learning
This kind of model is most often deployed in robotics or gaming;
enabling an agent to learn how to behave in an environment by interacting with it and receiving rewards or punishments.
- Recurrent neural network (RNN)s
RNNs are very good at understanding sentences and phrases in a contextual manner. They are often used for speech recognition, translations, or to generate text. This capability is otherwise known as natural language processing (NLP).
Other deep learning models include autoencoders and variational autoencoders; Generative adversarial networks (GANs); diffusion models; and transformer models.
The applications
Thanks to the sheer variety of models available to deep learning technology, it boasts countless applications – particularly within financial services. Here is a (non-exhaustive) list of uses, to give an idea of its scope:
- Computer vision – mines information and insights from images and videos; for quicker and more secure customer onboarding
- Speech recognition – interprets and analyses spoken language; for better Know-Your-Customer (KYC) processes
- NLP – extracts meaning from text and documents; for streamlined back-office processes
- Recommendation engines – tracks end-user activity and develops product or service recommendations; for hyper-personalisation and enhanced customer care
- GenAI – creates new content and communications; for enhancing the capabilities of developers or providing customers with AI agents
- Digital labour – performs the heavy lifting in operations; for robotic workforce support and augmentation
The use cases
As we have seen, deep learning can be
applied to numerous areas within financial services. To bring these examples to life, here is a real-world use case, whereby deep learning helped one organisation analyse financial data for equity trades.
In 2021, the independent algorithmic trading technology provider, Pragma, released execution algorithms with deep-learning capabilities. Pragma initiated the
project to see if deep neural networks could be applied to an execution algorithm’s micro-trading engine; governing decisions such as the routing, sizing, pricing and timing of orders – and deal with complex multi-dimensional trading challenges more effectively.
Following a beta launch in 2020, Pragma managed several controlled trials with its clients. It observed a significant improvement in execution quality, with an average shortfall improvement of 33% to 50% across billions of traded shares.
The future of deep learning
If we accept that technological innovation versus time assumes an ‘S’ curve, then we can safely predict that we have many more years – perhaps decades – until the full potential of deep learning and AI is laid bare.
The key to leveraging this transformative technology in the meantime is overcoming the implementation challenges – and ensuring our vast volumes of input data are clean, accurate, integrous, representative, and accountable. In the future, when we look back
on the developments in AI that are underway today, we will see the vestigial origins of these principles in our data protection regulations. Yet, to ensure the output of deep learning remains effective, equitable, and sanitary, they will need to be applied
scrupulously.